This invention relates to the art of seals and, more particularly, to a grommet for sealing electrical conductors extending through an opening between wet and dry sides of a substrate such as a watershield component.
The present invention finds particular utility in connection with sealing electric wires in a wiring harness extending through a watershield mounted on the inner panel of a vehicle door. Accordingly, the invention will be illustrated and described in detail herein in connection with such use. At the same time, as will become apparent hereinafter, it will be appreciated that the invention is applicable to the sealing of wires relative to the opposite sides of other substrates such as panels, plate components, or the fire wall of a vehicle, for example.
It is known, as shown in commonly assigned prior U.S. Pat. Nos. 4,696,848 and 4,957,803 to provide surface protectors or watershields on the inner panels of vehicle doors to protect the inner panels against the infiltration of water, dirt, dust, air, or the like. Generally, the shields are in the form of thin, flexible sheets of plastic material, such as polyethylene, having a peripheral contour corresponding to that of an inner door panel of a given vehicle. The shields are joined to the panels such as by pressure sensitive adhesive or other suitable fastening arrangements and, in vehicles having powered equipment such as windows, door locks, rear view mirrors, and the like, the electrical wires or wiring harnesses for such equipment pass through the watershield, whereby the conductors need to be sealed relative to the opening therefor in the watershield so as to preclude the ingress of air, water and dirt from the wet to the dry side of the shield. Heretofore, the opening for the conductors has been provided by cutting slits through the shield or, as shown in the above-mentioned U.S. Pat. No. 4,957,803 by providing a pocket comprising a plurality of closely spaced corrugations extending about a central opening through which a conductor extends. A portion or portions of the corrugations adjacent the opening are adhesively bonded to the conductor to optimize sealing therebetween.
The mere provision of slits in the shield for wires makes sealing across the shield extremely difficult, whereby the ingress of air, water and dirt across the shield to the dry side thereof remains a problem. While adequate sealing is achieved with the corrugated pocket arrangement described above, desired positioning of the conductor ends relative to the opposite sides of the shield is difficult to achieve because of the presence of the adhesive about the opening through which the conductors are passed. Further, if it becomes necessary to remove and replace the wires, the adhesive bonding between the pocket and wires resists separation thereof, making such removal difficult and, possibly, resulting in damage to the shield. Still further, if there is an electrical connector on an end of the wires which is diametrically larger than the conductors, assembly of the wires with the shield becomes difficult and sometimes impossible in that the connector cannot pass through the opening provided for the wires and, if the latter is enlarged such as by cutting, then sealing of the enlarged pocket opening with the wires can be a problem.